I feel like this line was crossed decades ago. As a child I saw the summary execution of Nguyễn Văn Lém on television. The suicides of Christine Chubbuck and Budd Dwyer, among others, were shown on TV too. Media in general has brought this kind of imagery into our homes for a long time.

I don't know what the answer is, when the problem is humanity. Social media platforms can do their best to limit what kinds of videos get posted, preventing the upload of content based on similarity to block-listed items, and moderators removing reported content, but beyond that I don't know...